The present invention relates generally to apparatus and methods for reducing the volume of a lung, and more particularly to apparatus and methods for isolating one or more regions of a lung using a clip that is deployed within a bronchus or other passage to reduce the effective volume of the lung.
Patients with chronic bronchitis or other chronic occlusive pulmonary disease (xe2x80x9cCOPDxe2x80x9d) may have reduced lung capacity and/or efficiency due to lung tissue breaking down. For example, in severe chronic pulmonary disease, e.g., emphysema, lung tissue may be damaged or destroyed, reducing the ability of the lung to effectively transfer oxygen. One of the problems with emphysema and like conditions is that the lungs become over-inflated, filling the chest cavity and preventing the patient from being able to inhale effectively.
In severe emphysema cases, lung volume reduction surgery (xe2x80x9cLVRSxe2x80x9d) has been suggested to improve lung efficiency. LVRS is performed by opening the chest cavity, retracting the ribs, and stapling off and removing a diseased or partially diseased portion of a lung. This may allow the remaining healthier lung tissue to inflate more fully within the chest cavity, thereby increasing lung efficiency. LVRS, however, is an extremely invasive procedure, and exposes the patient to substantial postoperative complications.
Accordingly, apparatus and methods for reducing the volume of a lung while avoiding the need for open surgery would be considered useful.
The present invention is directed to apparatus and methods for reducing the volume of a lung, and more particularly to closure devices, and to apparatus and methods for delivering closure devices, such as a clip, within a bronchus or other bronchial passage to reduce the volume of a lung and/or to isolate one or more regions of a lung.
In accordance with a first aspect of the present invention, a clip or other closure device is provided for closing a bronchial passage that includes a generally annular body or collar from which a plurality of tines extend. The annular body defines an opening therethrough, which may be generally circular and/or may have a predetermined asymmetrical shape that allows the clip to be detachably coupled to a delivery apparatus, such as that described below. The tines are movable between a contracted condition, and preferably are biased towards the contracted condition, but are deflectable towards the expanded condition.
In a first embodiment, the tines may extend generally parallel to one another along an axis extending through the opening in the annular body in the contracted condition. Alternatively, the tines may be biased to extend towards one another such that the annular body and the tines generally define a plane. The tines may be deflected axially, i.e., generally parallel to one another, to provide a delivery configuration, and further deflected radially outward to define the expanded condition.
In another embodiment, the collar may be collapsible towards a contracted condition and expandable towards an expanded condition. Preferably, the collar is biased to collapse towards the contracted condition and may be expanded towards the expanded condition, e.g., to deploy the closure device and/or to enhance engagement with surrounding tissue.
In yet another embodiment, the closure device may include a plurality of elongate elements connected by an intermediate hinged region. The elongate elements may include first ends defining tissue penetrating tips, and second ends opposite the hinged region. The first ends may be biased towards one another, but may be deflected radially outwardly by compressing the second ends.
In accordance with a second aspect of the present invention, an apparatus is provided for isolating a region of a lung that includes an elongate member, including a proximal end and a distal end having a size for insertion into a body lumen, such as a bronchial passage. A closure device, such as one of the clips described above, may be carried by the distal end, the closure device including a plurality of tines that are movable between a contracted condition and an expanded condition. A deflecting element, such as a ramped surface, an anvil, and the like, is also carried by the distal end of the elongate member. At least one of the deflecting element and the closure device is movable relative to the other for deflecting the tines outwardly towards the expanded condition for engaging tissue surrounding the distal end. The tines are collapsible towards the contracted condition, e.g., using their inherent bias or using a hammer also carried by the elongate member, for drawing the surrounding tissue inwards to substantially close and/or seal the body lumen, as described further below.
If desired, one or more other devices may be associated with the apparatus. For example, the apparatus may also include a source of energy, e.g., a radio frequency (RF) electrical generator, associated with the elongate member. At least a portion of the closure device may be coupled to the source of energy for delivering energy to surrounding tissue engaged by the tines. For example, first and second tines may be electrically coupled to first and second leads, respectively, that extend through the elongate member. The first and second leads may be coupled to opposite terminals of the RF generator, thereby providing a bipolar arrangement for applying energy to tissue. Alternatively, a single lead may be coupled to the closure device, and an external electrode may be attached to an exterior surface of a patient for providing a monopolar arrangement. In a further alternative, a first lead may be coupled to the closure device, and a second lead may be coupled to a location on the distal end of the apparatus.
Alternatively or in addition, a bronchoscope or other imaging device may be associated with the apparatus for viewing beyond the distal end of the elongate member. For example, the elongate member may be a bronchoscope, a bronchoscope may be slidably inserted through a lumen in the elongate member, or a separate bronchoscope may be independently used along with the apparatus.
A separate insufflation or aspiration catheter may also be provided or the elongate member may include a separate lumen extending between the proximal and distal ends. A source of fluid, e.g., oxygen or helium, or other substance, e.g., a corrosive and/or bonding agent, may be connected to the elongate member for delivering the substance to a location beyond the distal end of the elongate member via the lumen. Alternatively, a source of vacuum may be connected to the elongate member for evacuating fluid, e.g., air, via the lumen.
In accordance with another aspect of the present invention, a method is provided for reducing the volume of a lung using a closure device including a plurality of tines movable between contracted and expanded conditions, such as those described above. The closure device may be advanced within a bronchial passage to a predetermined location with the tines in the contracted condition. At the predetermined location, preferably a branch communicating with a region of the lung intended to be isolated and/or collapsed, the tines may be expanded outwardly towards the expanded condition to engage tissue surrounding the predetermined location, e.g., the wall of the bronchial passage. The tines may then be collapsed towards the contracted condition, thereby drawing the surrounding tissue inwardly to substantially close and/or seal the bronchial passage from air flow through the predetermined location into and/or out of the region to be isolated.
If desired, energy, such as electricity or heat, and/or an adhesive may be applied to the surrounding tissue after collapsing the tines to the contracted condition, thereby at least partially fusing or bonding the surrounding tissue together. Alternatively or in addition, a corrosive and/or bonding agent may be introduced into the region to be isolated before delivering the closure device for scarring and/or fusing tissue in the region to be isolated. In a further alternative, a conductive fluid, e.g., saline, may be introduced into the region to be isolated before closing the bronchial passage, electrical energy delivered via the fluid to damage or scar the tissue, and the fluid may then be removed.
The closure device may then be released from the distal end after the tines have been collapsed to close the bronchial passage. Alternatively, the closure device may be withdrawn from the predetermined location after applying energy and/or an adhesive, which may be sufficient to close the bronchial passage without the closure device.
Other objects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.